Conventionally, several kinds of guidewires that guide a catheter or the like used by being inserted in a tubular organ such as a vessel, a digestive tract, or a ureter or an intracorporeal tissue for a treatment or examination are proposed. Examples of such guidewires include a guidewire having a coil doubly-provided at a tip portion of a core shaft (for example, refer to U.S. Pat. No. 5,345,945 and JP-T-2006-511304) and a guidewire using a stranded wire including a plurality of strands as a coil at a tip portion (for example, refer to JP-A-2009-337).
There is also a guidewire that needs to pass through a narrow lesion location such as a relatively serious stenosis of a vessel. An example of such a guidewire is a guidewire having a coil with a tapered portion and with a small outer diameter of a tip portion (for example, refer to FIG. 5 in U.S. Pat. No. 5,345,945 described above).